1. Field of the Invention
The present invention is directed to a means for monitoring the operation of a fixing station of an electrographic printer that prints a web of continuous carrier material with a toner image containing color particles.
2. Description of the Related Art
High dependability demands must be met in the operation of a fixing station since, for example, one of the fixing rollers contained in the fixing station is heated to approximately 220.degree. C., and the carrier material conveyed through the fixing station can stick to the hot fixing roller. Given high conveying speeds of the carrier web, the fixing rollers turn very fast. When the sticking of the carrier material to the hot fixing roller is not noticed, then the carrier material being fixed at the moment wraps around the hot fixing roller, whereby carrier material that has already passed the fixing station can be drawn back into the fixing station opposite the conveying direction.
Given the use of continuous carrier material that has fold lines so that it can be drawn sheet-by-sheet from a stack or in turn folded sheet-by-sheet onto a stack after being printed (such as fan folded paper), the stiffness of the carrier material is greatly reduced along the fold lines. It is precisely at such fold lines that the carrier material easily sticks to the hot fixing roller during the fixing process, as is shown in practice. The fold lines are often the cause for the wrapping of the fixing roller. When the wrapping of the fixing roller is not noticed early on, then an increased work outlay is incurred given operation of the printer since printing must be interrupted, the carrier material must be removed from the fixing roller, one must wait for the printer to be operational again and the print operation that has already been carried out may possibly have to be repeated.